In a conventional carburetor as used with an internal combustion engine for a vehicle, one of the most troublesome features is the automatic choke mechanism. The automatic choke mechanism normally operates to control the position of the butterfly valve until the engine has achieved a predetermined temperature. If the automatic choke mechanism is not operating properly to close the butterfly valve, a fuel-lean mixture will be supplied to the engine, which can make starting of the engine difficult. On the other hand, if improper operation of the automatic choke mechanism results in the failure to open the butterfly valve after the engine is warm, flooding can occur, as well as excessive use of gasoline, thereby reducing the fuel efficiency of the engine.
Attempts have been made in the past to incorporate a fabric, wick-type material with carburetors in order to increase the vaporization of the gasoline. For example, the U.S. Pat. No. 663,699, is directed to a carburetor in which gasoline is introduced onto an absorbent pad composed of alternate layers of felt and wire gauze. In this construction, the air being drawn to the engine passes through the saturated felt to provide the gas-air mixture.
U.S. Pat. No. 583,126 dated 1897, discloses a carburetor in which an absorbent material, such as a sponge, is located within a wire mesh casing and gasoline is absorbed into the sponge and the air being drawn to the engine passes over the saturated sponge.
U.S. Pat. No. 1,605,966 discloses a carburetor system in which an anti-knock liquid is introduced into the air stream ahead of the carburetor. A wick extends down into a container which contains the anti-knock fluid and the air passing over the wick will vaporize the liquid before it is sent to the carburetor.